: :NO2 is Nitrogen Dioxide which I think is the case here, NO2 has 2 Oxygen atoms for every Nitrogen, this molecule decomposes to give more oxygen

: --Actually, it is nitrous oxide that's used in automotive applications, nitrogen dioxide is a poisonous gas. The single oxygen molecule of nitrous is released from the nitrogen at a much lower threshold than it takes to split the two diatomic oxygen for use in combustion. So even though you're behind by one stoichiometrically, you're ahead in net thermal energy gain.